Method of manufacturing stranded conductors



June 2, 1936. c. TRAUGOTT METHOD OF MANUFACTURING STRANDED CONDUCTORS Filed May 25, 1934 Patented June 2, 1936- PATENT OFFICE METHOD OF MANUFACTURING STRANDED CONDUCTORS Carl Traugott, Oldenburg, Germany, assignor to Norddeutsche Seekabelwerke Aktiengesellschaft. Nordenham,

Germany Application May 25, 1934, Serial No. 727,551

In Germany June 21, 1933 4 Claims.

This invention relates to the constructionand method of manufacture of a stranded conductor of the re-entrant type. By such a conductor is to be understood a stranded conductor in which each of the wires of which the conductor is com- 7 l5 them, they show a uniform current density in all parts of the cross-section of the conductor and are therefore free from the resistance increasing action of the skin effect. Conductors of this kind are thus particularly suitable for the trans- 20 mission of currents of high frequency and can for instance be used as conductors in carrier frequency cables.

According to the invention the individual wires of the stranded conductor change their position 25 not only within oneand the same wire layer, but each wire is led in such a manner that, when regarding a series of successive cross-sections of the stranded conductor, the cross-sections of the I individual wires follow cyclically a closed curve 30 one behind the other inthe same sequence through the entire cross-section of the stranded conductor or the cross-section of sectors of the stranded conductor.

Figure 1 of the accompanying drawing illustrates in cross-section a conductor manufactured according to the invention. Figure 2 illustrates a machine, in connection with which the manufacturing method according to the present invention is described. Figure 3 is a cross-secb tionof the machine illustrated in Figure 2.

Referring to Figure 1, thestranded conductor consisting of 61 wires is divided into two semicircular sectors which are laidaround a core wire a. The broken line b indicates the path 4 followed by each wire as it passes through all the layers within the cross-sectional area of each sector. As will be at once apparent, the stranded conductor according to the invention has the advantage that it has a particularly great copper 50 filling factor, as any considerable interstices in the cross-sectional area of the stranded conductor, which are not filled with copper, are avoided. It has for instance been found that the utilization of the cross-sectional area of the finished 5 stranded conductor amounts, without any subsequent drawing process, to about 75%. It may also be remarked that the loss in length of the individual wire is ,reduced to a minimum when laid in accordance with the invention.

The stranding machine consists of a stationary 5 spinning plate I in which are the kidney-shaped guiding slots 2 shownin Fig. 3, which are not visible in the representation of Fig. 2. In these slots 2 slide the bolts '3 of the bobbin holders 4, which consist of a frame 5 closed at the front, in which the bobbins 6 are journalled. The wire 1 runs out through a hole 8 in the front transverse part of the frame. The bolts 3 have an angular cross-section for preventing any undesired turning of the bobbin holders. 0n the rear side of the stranding plate I the separate bolts 3 of one sector are connected to one another in succession by a link chain I4, this link chain having its direction reversed at the points of reversal of the guiding slots 2 by rollers 9, of which at each slot one is driven from the'outside and by means of teeth imparts its motion to the link chain. In this way the bobbin holders 4 are moved along the path prescribed by the guiding slots, so that the individual wires are laid alternately in the inner and outer position. The laying itself is effected in the stranding machine illustrated by turning the spooling up device III in a manner known per se with respect to the stationary spinning plate. As there is a danger that the laying of the inner layer may take place not in the turning pressure-applying bearing H, but that the stranding point of this layer will wander automatically in the direction of the plate I, the spinning plate I has the hollow shaft provided on it, which extends up to the vicinity of the pressure-applying bearing, where with the outside of its head it forms a guide for the wires of the inner layer. The core wire iii of the stranded conductor is guided through this hollow shaft.

Instead of the'constructional form with a stationary spinning plate as illustrated, the machine may of course be so constructed that the spooling up device is stationary and the spinning plate 5 rotates. The method of stranding, which in this instance for the sake of simplicity is shown for two layers only, may also be employed for laying more than two layers, if further direction-reversing rollers for the link chain be interposed.

What I claim is:

1. A method of manufacturing a stranded electric conductorof the re-entrant type comprising a plurality of individual insulated wires in a stranding machine having bobbins which pay out I the individual wires, consisting ,in moving the bobbins relatively to one another during the stranding operation in such a manner that the cross-sections of the individual wires, when regarding a series of successive cross-sections of the finished stranded conductor, follow one another side by side without crossing one another cyclically along a closed curve in constant sequence through the entire cross-sectional area of the stranded conductor.

2. A method of manufacturing a stranded electric conductor of the re-entrant-type comprising a plurality of individual insulated wires in a stranding machine having bobbins which pay out the individual wires, consisting in moving the bobbins relatively to one another during the stranding operation in such a manner that the cross-sections of the individual wires, when regarding a series of successive cross-sections of the finished stranded conductor, follow one another side by side without crossing one another cyclically along a closed curve in constant sequence through the whole of the cross-sectional areas of sectors of the cross-sectional area of the stranded conductor.

3. A machine for the manufacture of a stranded electric conductor of the re-entrant type comprising a plurality oi. individual insulated wires, said machine comprising a plurality of stranding bobbins for paying out the individual wires, a spinning plate supporting said bobbins, guides in said plate for the bobbins, and link chains for imparting movement to the bobbins in said guides whereby they are caused to travel one behind the other in constant sequence along a closed curve without intersecting one another or being "intersected by other curves.

4. A stranding machine for the manufacture of a stranded electric conductor of the re-entrant type comprising a plurality of individual insulated wires, said machine comprising a spinning plate, guides in said spinning plate corresponding to the number of sectors forming the crosssectional area of the conductor, a plurality of bobbins for paying out the individual wires, and means for moving said bobbins along a closed path in said guides without intersecting one another or being intersected by other curves.

CARL TRAUGO'IT. 

